<!DOCTYPE html>
<html>
  <!-- Test: if one radio in a group has the required attribute and no radio is
             checked, all radio in the group should suffer from being missing. -->
  <link rel='stylesheet' type='text/css' href='style.css'>
  <body>
    <input class='invalid' id='i1' name='foo' type='radio' required>
    <input class='invalid' id='i2' name='foo' type='radio'>
  </body>
</html>
